Fire-extinguishing composition having a low freezing-point.



niu'rnn sa GEORGE E. FERGUSON, OF NEW YORK, N. Y., ASSIGN OR TO PYRENEMANUFACTURING COMPANY, A COBPORATION OF DELAWARE.

FIREE XTINGUISHING COMPOSITION HAVING A LOW FREEZING-POINT.

No Drawing.

T5 all whom it may concern Be it known that I, GEORGE E. Fnncnson, acitizen of the United States, and resident of the city. county,'andState of New York,

have invented certain new and useful lnr' provements 1nFire-Extinguishing Composition Having a Low l ieezing-Poinhof which thefollowing is a specification.-

The object of this invention is'to produce a composition, suitable foruse in ex- ;ftinguishing fires, characterized by a low freezing point,and further, to produce a fire extinguishing composition in which the.fire extinguishing substance thereof acts as a solvent for thesubstance whose inclusion produces the low freezing point. Carbontetrachloricl has been selected as illustrative of a solvent which,being a solvent for many other compounds, is useful for many purposes,among which line extinguishing compounds may be mentioned, carbon tetrachlorid being non-inflammable.

The extensive uses to which carbon tetrachlorid is put, make itdesirable to lower its'norinal freezing point (which in the chemicallypure state is l9.5 C.) to permit its use in temperatures where extremecold Weather prevails; that it may be utilized as a liquid and at the.same time maintain al of its useful properties.

lVith this in mind, Ihave performed a large number of experiments toascertain. if some underlying principle can be made to govern. thisdepression of the freezing point.

It is a well known fact that, considering inorganic compounds and theinorganic solvents, that the depression of the freezing poiht dependsupon the solubility of the salts,-used and the degree of dissociationwhich takes place When these saltsare dis solved in the solvent (whichsolvent, in most cases, is Water).

The laws governing the depression of the freezing point for electrolytesis simple:

1. The freezing point of a solution is lower than that of the'puresolvent.

2. The depression of the ,freezing point is proportional "to theconcentration of the solution. f I

' 3. If t degrees be the depression produced by the presence of pil-grams ofsub- Specification of Letters Patent. Patented June 25 1918Application filed October 20, 1914. Serial No. 867,581.

stance in 100 grams of the solvent, then the molecular depression (wherem is the molecular weight of the dissolved substance).

These laws do not hold good in the depression of the freezing point ofcarbon tetrachlorid. A. good example of this is in the solution of acompound like azobenzene (C ILN C H which is very soluble in carbontetrachlorid. When this substance is added the result is a higherfreezing point than that of the carbon tetrachlorid alone, and the moreazo compound dissolved the higher the freezing point.

lVhen a number of such experiments were tried and, no principle. couldbe established, it. was decided to try. out all the connnen ciallypossible" substances which could be dissolved in carbon tetrachlorid, toascertain which would depress the freezing point. It was found thatamong the great variety of compounds tried out about 150 accomplishedthe desired result.

It is understood that some of these co1npounds would prove detrimentaltothe use of carbon tetrachlorid under certain condi tions while theymight prove "ery able under others.

To simplify the list,- it 'was thought best to classify these substancesunder different chemical roups, such as, (l) esters and ethers; (2 aminsand aminocon'ipounds; (3) aldehydes and ketones; (4) alcohols; (5) oils;(6) hydrocarbons, substitutes and derivatives; (7) phenols and phenolderivatives; (8) terpenes, camphors and (9) acids, etc.

About the only generality which can be made in regard to all thisinvestigation is the fact that most compounds which are in the liquidstate at normal (room) te1nperature and which are soluble in carbontetrachlorid, lower the freezing pointof the carbon tetrachlorid and,vice versa, most of the compounds which are solid at normal temperatureand soluble in carbon tetrachlorid do not lower the freezing point butinmost cases raise it. There are, however,

enough exceptions to this generality to renaccept- .point.

der it impossible of general application as a 'rule. 7

In this investigation no attem t was made to determine the quantity ofsu stance dis:

solved in a known amount of solvent to ro duce an observed depression ofthe freezing- It was thought that sufiicient knowledge was gained indetermining just what substances would accomplish the desired depressingefi'ect on the freezing point.

, Considering the group of aldehydes and, ketones, which are closelyrelated, the following may be taken as a definition:

Aldehydes are the oxidation products of primary alcohols and have thegeneral formula C H Ci.

' C H CHCHCHO; citral, C H CHG; chlo retone, (combination of acetone andchloroform) furfurole, CJ-LOGHO; paraldehyde,-

CHO; acetone, CH COCH Ketones are the oxidation products of secondaryalcohols.

A primary alcohol has the hydroxyl group (OH) linked to an end carbonatom of the series and contains the group CHAOH).

A secondary alcohol contains the group CH(OH) and has the hydroxyl group(GH) linked to a middle carbon atom.

The following are examples of this group anisic aldehyde, C HAOCHQCHO;acetic aldehyde, CH CHO; acetal (combination of acetaldehyde and ethylalcohol, CHQC-H- (OC H) acetophenone (phenyl methyl ketone) J H CO (oilof bitter almonds) oinnamio aldehyde;

(C H,,O) salicylic aldehyde, 011C 11,-

It is obvious that it is impossible to cover every compound, in themanner described, to ascertain if the freezing point of carbontetrachlorid could be lowered by dissolving the possible.

CH mono chlor acetone, benzaldehyde C H CHQ compound therein. I'have,however, made tests in each class of compounds with com merciallypossible examples in each class. What future developments may be madeto- .ward thereduction of thecost' of a number of the-expensivecompounds, thus rendering the same commercially possible, isproblematicalbut my "experiments and testsjshow v.

thatit-is' possible tipgeneralize in these diffGI'GIIlBfdlVlSlOIIS orclasses.

7' F our "hundred and thirty experiments 'we re'performed the substancesselected be- 1. A fire extinguishingcomposition hav- 1 ing a lowfreezing point, comprising carbon tetrachlorid and acetophenonedissolved therein.

2. A fire extinguishing composition having a low freezing point,comprising'a solvent and acetophenone dissolved therein.

A fire extinguishing composition comprising a non-inflammable solventand aceto henone dissolved therein said com osition having a freezingpoint substantially lower than that of the solvent.

Signed at the city, county and State of New York, this 8th day ofOctober, 1914.,

GEORGE E. FERGUSON.

Witnesses:

HOWARD W. CHAPMAN, LEWIS J. Doom'r'rnn.

